1. Field of the Invention
This invention relates to security systems, multi-output sensors and adjusting the sensitivity of the multi-output sensors. More particularly, this invention relates to a method for dynamically responding to only one output of a multi-output sensor based upon certain preset criterion.
2. Background
A security system includes any life, safety, and property protection system. A security system comprises a local security system located in a commercial or residential premises in communication with a remote monitoring station. The local security system typically includes a central control panel that communicates with a number of sensors via a wired or wireless path. The control panel has the ability to notify local emergency services and/or a remote monitoring station of an alarm condition via a telephone dialer. The local security system also includes a local alarm generating section responsive to the sensors. The sensors are deployed throughout the commercial or residential premises. The sensors are separated into zones. Typically, at least one sensor is deployed in each zone.
A sensor is used to detect many different types of events, e.g., glass break, motion, temperature and shock. A single sensor has several different sensitivity levels. The types of sensors include a single output sensor and a multi-output sensor. The sensitivity of a single output sensor can be manually adjusted using switches during installation. A multi-output sensor includes a multi-loop transmitter to transmit the multiple outputs. An output of the multi-loop transmitter corresponds to a different sensitivity level. One of the outputs corresponds to a malfunction of the sensor.
For example, a multi-output sensor may have low, medium, and high sensitivity outputs to accommodate different room environments. Such low, medium, and high sensitivity outputs may, for example, correspond, respectively, to an intruder taking three steps, two steps, or one step in a protected space. The control panel can only respond to one output from the multi-output sensor, i.e., one loop from the multi-loop transmitter. The sensitivity of the sensor can be set during the installation of the security system.
U.S. patent application Ser. No. 10/893,037(the '037 Application”) entitled “Method for Remotely Changing the Sensitivity of a Wireless Sensor” filed on Jul. 15, 2004, assigned to Honeywell International, Inc. describes a method for remotely programming an apparatus to respond to only one loop received from the multi-loop transmitter even if multiple loops are received. The '037 Application describes a method to program an apparatus remotely to operatively connect one of a first or second output.
The apparatus receives all of the multi-loop signals from the multi-loop transmitter and is programmed to only respond to one. The loop number of the sensor is assigned a different sensitivity level. During installation, the installer chooses the loop number associated with the desired sensitivity setting. At a later time, the installer can change the sensitivity of the sensor by remotely changing the loop number programmed into the apparatus.
However, the apparatus will always respond to the same loop number and have the same sensitivity, unless the installer reprograms the apparatus. The apparatus described in the '037 Application cannot respond to a different loop number depending on conditions within the protected premises. In other words, there is a need to be able to change the sensitivity of the sensor in a dynamic fashion to account for the environment conditions and status of the security system.